Border guards could not have legally arrested Huawei Technologies executive Meng Wanzhou at Vancouver’s airport last December, says a lawyer representing the Canadian government.

Meng’s lawyers argue that officers with the Canada Border Services Agency should have immediately executed a provisional arrest warrant instead of questioning her for three hours before the RCMP arrested her.

The Chinese tech giant’s chief financial officer was arrested Dec. 1, 2018, at the request of the United States, which is seeking her extradition on fraud charges linked to the alleged violation of sanctions against Iran.

Crown prosecutor Diba Majzub told a B.C. Supreme Court judge Tuesday that border officers are required by law to conduct an admissibility examination on all travellers entering Canada.

He said they aren’t legally empowered to arrest people under the Extradition Act and the Crown has provided 150 examples of cases in which border officers were involved but were not the ones to execute such warrants.

The RCMP Act specifically gives the Mounties the power to execute all warrants, Majzub added.

Meng’s arrest has sparked a diplomatic crisis between Canada and China. She denies any wrongdoing and her lawyers are in court seeking further documents ahead of her extradition trial in January.

Her lawyers allege that border officers, the RCMP and the Federal Bureau of Investigation conspired to conduct a “covert criminal investigation” at the airport and they’re requesting documents that they believe would back up that claim.

The defence has described communications between the three agencies on the day before Meng’s arrest as improper and alleged border guards violated her charter rights when they seized her electronic devices.

Majzub said the FBI notified Canada’s border agency on Nov. 30, 2018, that a person who was subject to a provisional arrest warrant might be coming through Vancouver’s airport.

The case law demonstrates that the FBI’s advisory was legitimate and necessary for Canada to enforce its border, he said.

“Is it evidence of an ulterior motive, an abuse of process, or is it in fact, normal conduct that (allows) the CBSA to do its job?” Majzub asked.

He also argued that there is a legal line between a customs and immigration examination and an investigation of a criminal offence in Canada. Before that line is reached, charter rights are not engaged, he said.

“There was never a danger of that line being crossed,” Majzub said. “There was no criminal investigation in Canada. They’re entitled to go as far as they need to determine whether she’s admissible to Canada.”

Border guards are entitled to examine a traveller’s goods, and that has been legally interpreted to include electronic devices, he said. CBSA officers seized her devices and obtained the passcodes before passing them on to the RCMP.

The Crown has said that neither border officers nor police searched her devices and since the FBI has said it doesn’t require them, Canada has been trying for the past two months to return them to Meng.

The defence has argued that border guards seized the devices and questioned Meng about Huawei’s business dealings in Iran in order to further the U.S. case against her.

However, Majzub said border guards went as far as they did because they had legitimate concerns about possible criminality and national security.

If they had deemed her inadmissible to Canada, it’s unlikely that she would have been ordered to immediately return to China, and the RCMP could have executed the warrant while she was in detention or awaiting a hearing, he said.

The defence has noted that border guards did not actually complete their examination of Meng and instead suspended the process, at which point police executed the warrant.

Meng, who is also the daughter of Huawei founder Ren Zhengfei, is free on bail and living in her multi-million dollar home in Vancouver while she awaits her trial.

The U.S. alleges she lied to HSBC about Huawei’s business dealings in Iran, putting the company at risk of prosecution for violating sanctions.